I have thick, black/brown Asian hair.
About 5 months ago I used Garnier Nutrisse Ultra Color R3-Light Intense Auburn to give my hair a reddish tint/color. My roots have grown out now and I'm sick of the red color, so I want to take my hair back to its dark color.

I tried using a Medium Ash Brown color over the red hair, and my hair looks fairly brown, but my hair still shines that red color and my 2 inch roots are still noticeable.
Any suggestions on how to get the red out of my hair? Would a Blue-Black hair dye get this red color out, or..